1. Field of the Invention
The present invention relates to an RFID monitor system, and more particularly to an asset monitor system.
2. Description of the Prior Art
Generally speaking, the radio frequency identification (RFID) applied to a zone location are divided into two groups. The first one is RFID reader location and the second one is IR (infrared rays) location.
In the RFID reader location, a plurality of RFID readers are installed in monitored spaces and radiated power of the RFID readers are set to adjust the coverage area. The RFID readers are connected to a rear terminal by a network, and the RFID readers receive a signal sent from a remote tag to acquire a location of the tag. However, the RFID reader location is unfavorable to apply in an accurate small-area location because of higher cost for using a large number of RFID readers.
In the IR location, a plurality of IR transmitters are installed in monitored spaces. The IR transmitter sends a location identification to an electronic tag with an IR receiver, and the electronic tag transmits a signal included the location identification to a reader. However, the location identification easily disappears when the IR receiver of the tag is covered by clothes or other objects.
ZigBee is a wireless technology developed as an open global standard to address the unique needs of low-cost, low-power, wireless sensor networks. However, ZigBee has two main disadvantages: first one is a large number of data are received by readers to increase electricity consumption of electronic tags. The second one is a plurality of routers are used to pass through responded messages to increase difficulty of certifying the actual location.